Simply, turquoise is not white. There are a lot of trade names for mineral out there that will conflict with that, but turquoise is called turquoise because of its color. When you see something called 'white turquoise' or 'white buffalo turquoise' it is either howlite or magnasite. People get more money if they tack turquoise on the name. Real turquoise is not all the same color, but varying shade of blue. Not white, sorry.
There is the mineral called Sacred Buffalo Turquoise. This is turquoise, and very rare. If I got my hands on a piece, I'd never sell it. You can read about Sacred Buffalo Turquoise here.
I've got nothing against promoting your goods, but when you get to the point where you are purposely decieving people, it makes me shake my head. Howlite and magnasite are beautiful all on their own. If you are lucky enough to have a piece of Sacred Buffalo Turquoise, you are blessed. If you have the other stuff, don't feel bad. I see it being sold all over the southwest, and if I say anything, I'm told I just don't know what I'm talking about. So be it. When I list a cabochon, I make every effort to be as honest as I can. I have dyed turquoise and howlite, and I want everyone to know that.